A novel etiology for automatic mode switching and ventricular noise reversion alerts: pulsed field ablation

Artifactual recordings on cardiac implantable electronic devices (CIEDs) may be physiologic oversensing or a harbinger of lead failure with implications of requiring lead revision. 1,2oise reversion is an algorithm that causes the pacing functionality of devices to switch to asynchronous pacing when there is repetitive sensing at high rates. 3With the recent approval from the U.S. Food and Drug Administration for two pulsed-field ablation (PFA) systems and concurrent increased uptake of the technology for catheter ablation of atrial fibrillation, artifactual recordings specific to PFA might be recorded from a CIED, warranting distinction from other environmental sources of oversensing and noise reversion alerts.A 76-year-old male patient with a medical history of ischemic cardiomyopathy and prior substrate modification for a VT originating from left ventricular anterior/anteroseptal scar developed persistent atrial fibrillation.He had a dual-chamber implantable cardioverter defibrillator (Gallant DR, Abbott, Chicago, IL) programmed DDDR (70-100) with automatic mode switching to DDIR programmed at an atrial rate of 160 bpm.He presented for catheter ablation using the pentaspline PFA catheter (Farawave, Boston Scientific, Marlborough, MA).Device therapies were turned off before the procedure and a preprocedure device interrogation showed normal device function and no significant events other than persistent atrial fibrillation.Upon interrogation of the device postprocedure, two automatic mode switching episodes (Figure 1) and four noise reversion alerts (Figure 2) were noted on routine post-ablation device interrogation.During delivery of each lesion, unsynchronized therapeutic waveforms in a hierarchical set of microsecond scale biphasic pulses are delivered. 4With the increased use of PFA nationally and internationally, patients with CIEDs are likely to record such artifactual tracings.It is valuable for all clinicians interacting with CIEDs to appreciate these patterns of oversensing when investigating device alerts during interrogations, particularly as these findings are likely to become more prevalent with continued uptake of PFA technologies.